Service:

import { Injectable } from '@angular/core';
import { HttpHeaders, HttpClient } from '@angular/common/http';

constructor(
    private http: HttpClient
) { }

private API_GET_BARCO_BY_CANTIDAD = `${GlobalVariables.URL_NODE}/barco/encontrar/c/?barcosC=`;

private header = new HttpHeaders({
    'Content-Type': 'application/json'
});

public getBarcoByC(cantidad: Number): Observable<any> {
    return this.http.get<any>(this.API_GET_BARCO_BY_CANTIDAD + cantidad, { headers: this.header });
}

API:

const router = Router();
const Barco = require('../models/Barco')

router.get("/barco/encontrar/c/", getBarcosByC);

async function getBarcosByC(req, res) {
  try {
    let cantidad = parseInt(req.query.barcosC);
    var barcos = await Barco.find().limit(cantidad).sort({ 'ultima_actualizacion': -1 })
    console.log(`Cantidad: ${barcos.length}`)
    if ('err' in barcos) return res.status(barcos.codestatus).json(barcos.err);
    return res.status(200).json(barcos);
  } catch (err) {
    console.log("[BarcosApi] getBarcosByCError", err);
  }
}

Console: temp0.error.text Gives back the whole index.html page as error.text

All GET requests have the same respond(index.html), while POST, UPDATE, DELETE works flawlessly